Do the nasty. Get down to business. Screw. Shag. Root. Bonk.

For every silly nickname we use for sex, there's a totally legit reason why you should be having more of it. To prove our point, we've pulled together a comprehensive list of the mind-boggling benefits of hitting the sheets.

From boosting your immune system to releasing aggression, here are the many ways it pays to play dirty.

1. US endocrinologists at Columbia University found that women who have sex at least once a week have more regular menstrual cycles than those who are less sack-happy.

2. Sex makes you happier than money does, according to a recent US study.

3. Work off those Mars Pods without hitting the treadmill. One 30-minute roll in the hay burns about 840kJ.

4. Avoid cracking the shits at work. Nookie helps the brain produce neuro-transmitters, chemical messengers that help mellow our moods.

5. Get more zzzzs. Getting a sensual massage followed by some dancing in the sheets releases sleep-inducing endorphins so you snooze soundly.

6. Post-romp, you'll experience a surge in the hormone prolactin, which develops new neurons in the brain's olfactory bulb, improving your sense of smell.

7. Unless you're a kinky, wayward politician, it's free!

8. Kick colds to the curb. Researchers at Wilkes University, US, found that having sex once or twice a week boosts the immune system by 30 per cent.

9. Protect pearly whites by stepping up to the mic. Semen contains small amounts of zinc, calcium and minerals proven to fight tooth decay.

10. Watch a Sex and The City marathon without constant bathroom breaks. Sex tones the pelvic muscles that support your uterus, bladder and bowel, meaning better pee control.

11. Post big O, you'll get a surge of oxytocin. The overload releases endorphins, which help alleviate pain from arthritis and menstrual cramps. Hallelujah!

12. Take him to your level. Family therapist Michael Gurian, author of What Could He Be Thinking?, says a man's oxytocin level matches ours after his happy ending.

13. Relationship expert Scott Haltzman, author of The Secrets of Happily Married Men, says women absorb testosterone men secrete in semen. "Increased testosterone can have energy-boosting effects in women."

14. Blow 'em away in your bikini. According to researchers, regular shagging can tighten your tummy and firm your bum. What's not to like?

15. Shag his ticker into shape. A study at Queen's University in Ireland found men who have sex three or more times a week can cut their risk of heart attack in half.

16. The study also found regular romps will halve your man's chances of suffering a stroke.

17. Prove that yes, nice girls do do that.

18. Forget flowers, sex is an easier (and heaps more effective) way to make up after a fight.

19. "There's a thin line between pain and pleasure. Sex can help distinguish between the sensations," says nurse Evelyn Resh.

20. Stir creative juices. "When you're together long-term, sex can become boring," Resh says. "Coming up with new ways to keep things interesting improves the imagination."

21. Two little words: "I'm pregnant!"

22. Sex can trigger the onset of labour when you're at term. "Semen contains prostaglandins," Resh says. "When they're against the cervix, prostaglandins help it dilate and induce natural labour."

23. Getting busy regularly can improve your flexibility. Cirque du Soleil, here you come!

24. Cross language barriers. He speaks only Italian. You're from Wollongong. But in the boudoir, you both speak the universal language of l-o-v-e (nothing gets lost in translation).

25. Love the skin you're in. For some people, regular sex can boost body image.

26. Keep closer tabs on your health. Sex means exploring your body - and your partner's - so you'll notice if things feel or look wonky and might need a doctor's attention.

27. Seriously pissed off? Don't scream your head off - save your voice and have sex to release tension.

28. Improve your communication skills. Speaking up about what's working (or not) in the sack can help you express yourself in other parts of your life.

29. Use it or lose it. "The more you have sex, the more likely you'll be to continue to produce testosterone, one of the primary hormones responsible for sexual desire," says Michele Weiner Davis, author of The Sex-Starved Wife.

30. Give him a booty biscuit. "Guys see sex as a sign of approval from their partner," Weiner Davis says.

31. Add your share of smut to the girls' night cocktail chatter. Even bad sex can be fun to dish about.

32. Express some of your more risqué emotions and behaviours - aggression, domination - in the comfort of your own bedroom. (S&M, anyone?)

33. Yes, tonight, dear - I have a headache. Recent studies have shown that doing the horizontal hustle can bring temporary headache relief.

34. "When things go well in bed, you feel more confident and powerful in other parts of your life," says sex therapist Sandor Gardos.

35. "Increase the amount and quality of cuddle time," says psychologist Laurie Mintz. "The best comes immediately after the orgasm."

36. Activate your tastebuds. "Your sensitivities are heightened after sexual intercourse," Gardos says. "That bottle of wine or chocolate bar will taste even better.

37. Strengthen your core. It's like pilates without the annoyingly perfect instructor.

38. Having sex eases the tension around sex itself. (Circular logic, but true!)

39. Best excuse in the world for pricey lingerie.

40. How else will you get better at it?

41. Give your guy a helping hand. According to the Journal of the American Medical Association, the more he ejaculates, the less likely he is to develop prostate cancer.

42. "Good sex creates more love each time," Mintz says. "It is 'making love'."

43. Share a laugh about your O-face... or not.

44. Vitalise the va-jay-jay. Rises in blood flow to the pelvis keep the oven in good order.

45. It's the perfect excuse to crank some Prince and then follow it up with Marvin Gaye.

46. Because it's 3am at 30,000ft, and your red-eye doesn't land for two hours.

47. You can make like a leading lady and re-enact steamy scenes from your fave flicks. Start with 9½ Weeks.

48. Curb irritability. "Tactile stimulation soothes nerves," says Resh.

49. Be at one with nature. After all, birds do it. Bees do it. Even educated fleas do it.

50. Because the clitoris is the only organ whose sole function is pleasure and it's a shame to let that go to waste.

51. Skip the Botox. In his book, Secrets of the Superyoung, neurophysiologist David Weeks writes: "An active sex life slows the ageing process."